This invention is directed to a new treating agent for fillers which yields a substantially different surface treatment. In particular, various types of fillers with surfaces containing a reactive group such as .tbd.SiOH, AlOH, or TiOH, for example, ring open oxa-silacycloalkanes to form carbinol treated surfaces.
Dow Corning's U.S. Pat. No. 5,290,901 (Mar. 1, 1994) describes the formation of certain carbinol functional silicones by reacting a cyclic silyl ether with (i) a silanol (i.e. .tbd.SiOH) endcapped silicone fluid, or (ii) a silicone resin. While we form carbinol functional materials with similar ethers (i.e. an oxa-silacycloalkane), we use inorganic pigments, metal oxides, metal hydroxides, or silicate minerals.
Inorganic pigments, metal oxides such as silica (SiO.sub.2), metal hydroxides, and silicate minerals, are not the same as or similar to silanol endcapped silicone fluids or silicone resins in the '901 patent. Although silica and silicate minerals are compounds of silicon, unlike silanol endcapped silicone fluids and silicone resins of the '901 patent, silica and silicate minerals do not contain .tbd.Si--C bonds.
Thus, silicone fluids and silicone resins belong to the class of organosilicon compounds. Their characteristic feature is that they have at least one direct .tbd.Si--C bond in the molecule. Silica and silicate minerals, on the other hand, are not classified as organosilicon compounds, since they contain no carbon atom. Where a carbon atom does exist, (i.e. organic silicates), it is attached to silicon only through oxygen. Hence, materials treated in Dow Corning's '901 patent and in our invention have little in common.